A man reacts near a house tilted by floods in the village of Krupanj, west from Belgrade, May 19, 2014. REUTERS/Marko Djurica

The worst rainfall to hit Serbia and Bosnia in 120 years has killed upwards of 40 people and destroyed entire towns.

"The physical destruction is not less than the destruction caused by the [1992-95 war in Bosnia]." Bosnian Foreign Minister Zlatko Lagumdžija told a news conference. "During the war, many people lost everything. Today, again they have nothing."

He noted that more than 100,000 houses and other buildings in Bosnia were no longer fit to use.

More than one million people live in the affected areas. About 500,000 people have been evacuated or left their homes and at least 95,000 homes are without power. Over a million people have been cut off from clean water supplies.

"The situation is catastrophic," Serbian Prime Minister Aleksandar Vucic said earlier this week. "These are the kind of waters not seen in 1,000 years, let alone 100."

The mayor of Mali Zvornik, which is located on Serbia's border with Bosnia, said an "entire hill" was threatening to slide into the River Drina and flood the town.

The government in Bosnia says more than 1 million people, or a quarter of the population, have been affected by the flooding and landslides. REUTERS

About 300 landslides have complicated rescue efforts as houses and cars are being buried, bridges are crumbling, and roads have been rendered impassable.

The photos are stunning and show the heroic rescue effort underway.

Men paddle towards homes during heavy floods in the village of Vojskova, May 19, 2014. REUTERS/Srdjan Zivulovic A man looks at flood waters in the town of Smedarevska Palanka, southeast of Belgrade, May 20, 2014. REUTERS/Antonio Bronic

An aerial view of the flooded city of Brcko, May 18, 2014. REUTERS/Marko Djurica

An aerial view of flooding in Orasje, May 18, 2014. REUTERS/Marko Djurica

An aerial view of the flooded city of Orasje May 18, 2014. REUTERS/Marko Djurica A Serbian army soldier rows a boat as he searches for people to be evacuated in the town of Obrenovac, southwest of Belgrade, May 16, 2014. REUTERS/Marko Djurica People carry their belongings as they evacuate from their flooded houses in Topcic Polje, near Zepce May 16, 2014. REUTERS/Dado Ruvic Asim Skopljak talks on a mobile phone as he walks near a car stranded in mud on a street that was hit by floods in Topcic Polje, near Zepce May 16, 2014. REUTERS/Dado Ruvic A vehicle stranded in mud is seen on a street that was hit by floods in Topcic Polje, near Zepce May 16, 2014. REUTERS/Dado Ruvic A member of the rescue team carries a women as they leave her flooded house in Topcic Polje, near Zepce May 16, 2014. REUTERS/Marko Djurica People look out from their apartments as they wait to be evacuated in the town of Obrenovac, southwest of Belgrade May 16, 2014. REUTERS/Marko Djurica People stand on a terrace of their flooded house as the wait to be evacuated in the town of Obrenovac, southwest of Belgrade May 16, 2014. REUTERS/Marko Djurica Serbian army soldiers evacuate people from a flooded house in the town of Obrenovac, southwest of Belgrade May 16, 2014. REUTERS/Marko Djurica A Serbian rows a boat past flooded ambulance vehicles in the flooded town of Obrenovac, southwest of Belgrade, Serbia May 17, 2014. REUTERS/Marko Djurica Serbian army soldiers evacuate a boy from a flooded house in the town of Obrenovac, southwest of Belgrade, May 17, 2014. REUTERS/Marko Djurica Serbian army soldiers evacuate people in amphibious vehicles in the flooded town of Obrenovac, southwest of Belgrade May 17, 2014. REUTERS/Marko Djurica

Residents of Obrenovac are now living in a temporary community in Belgrade.

Evacuees from the Serbian town of Obrenovac are seen lying on beds in a shelter hall in Belgrade, May 18, 2014. REUTERS/Marko Djurica

The floods will devastate both the Serbian and Bosnian economies, which rely heavily on their agricultural sectors.